This invention pertains to a control system for a tethered-type engine-powdered model aircraft, and more particularly, to such a system which accommodates the use of three control wires--two for elevator control and one for throttle control.
The flying of such aircraft is an extremely popular hobby. People involved in this hobby have a substantial interest in being able to provide smooth, full, precise, easily applied control over such an aircraft, in order to obtain maximum performance and enjoyment.
Two-wire control systems, which have been widely used in the past, typically provide simply for elevator control. With such a system, an operator has no opportunity, while an aircraft is in flight, to change the throttle setting. Such systems obviously do not afford the fullest possible control.
A number of three-wire systems have been proposed in the past, but these have, for a variety of reasons, also not been entirely satisfactory. A complaint commonly found with such prior systems is that the tension which exists in the three wires in the system, with an aircraft under flight, is not equally distributed in the wires. A result of this is that smooth precision control is difficult. For example, such unequally shared tension tends to produce unwanted control functions. Further, prior three-wire systems are characterized by interconnections between moving parts which introduce a considerable amount of friction. High friction seriously impairs smooth precision control, and in fact introduces quite jerky and erratic control.
A general object of the present invention is to provide a novel three-wire control system for a tethered-type model aircraft which enables smooth precision control of a flying aircraft, and which specifically and significantly avoids the disadvantages and drawbacks of prior art systems.
More specifically, an object of the invention is to provide such a system wherein, under substantially all operating conditions with an aircraft flying, tension in the tethering lines is substantially equally distributed.
A further object of the invention is to provide a system of the type generally outlined wherein low-friction pivot connections are provided between the moving parts, which connections greatly minimize friction, and enhance the smoothness and precision capabilities of flight control.
Yet another important object of the present invention is to provide a control system as outlined wherein control of a line or wire for changing throttle speed has no effect on the disposition of elevators, and vice versa.
Another point which should also be mentioned preliminarily, is that existing tethered aircraft control systems are often extremely difficult for a beginner to manipulate successfully. Until such a person gains a "feel" for the handling of such a craft, he can easily overcontrol or overcompensate in his efforts, and in the past this has often resulted in an aircraft crashing. Still a further object of the present invention, therefore, is to provide a control system as so far outlined which also is especially suited to handling by a beginner.
Featured by the invention is a special multiple-link linkage arrangement, wherein links are interconnected for relative pivotal movement through low-friction pivot connections. Links in this arrangement provide locations for the attachment of the ends of the three control lines contemplated for use in the system. In the system described herein, slightly different modifications of such a linkage arrangement are provided for use both in a hand-held control device, and within the structure of a model aircraft using the system.
As an aid to a beginner in manipulating a device constructed in accordance with the invention, the above-mentioned low-friction pivot connections, through inhibiting jerky control, tend to prevent overcompensation. Further, a unique locking means is provided, as will be described, which enables the throttle control mechanism in the apparatus to be locked in an infinite number of different positions so that, once a satisfactory throttle position (for the beginner) has been attained, this can be maintained without requiring his attention.
As will become apparent from the description which now follows, the novel linkage arrangement proposed by the invention may be incorporated into a variety of hand control devices which offer various means for introducing elevator and/or throttle control. By way of description herein, several such devices are discussed.
Various other features and advantages offered by the invention will become apparent as the below description thereof is read in conjunction with the accompanying drawings.